A bladder-neck opening test using alfuzosin, a new alpha-adrenoceptor blocking agent, was carried out in 21 patients with spinal cord injury. The efficacy of alfuzosin was assessed with 4 simple urodynamic parameters: micturition, residual urine, posterior urethral pressure and diameter. Both mean urethral pressure and diameter were significantly affected after the administration of 5 mg i.v. alfuzosin. The test was clinically positive in 18 patients: 11 out of 13 patients using intermittent catheterisation or continuous drainage urinated and 6 out of 8 patients already tapping had reduced residual urine volumes. A decrease in posterior urethral pressure was also observed in 2 out of 3 patients who did not respond clinically to alfuzosin. Alfuzosin was well tolerated during this test. Oral alfuzosin should therefore be investigated in patients who gave a satisfactory response to such a test.